On Christian Doctrine

33. But to desire to predict the characters, the acts, and the fate of those who are born from such an observation, is a great delusion and great madness. And among those at least who have any sort of acquaintance with matters of this kind (which, indeed, are only fit to be unlearnt again), this superstition is refuted beyond the reach of doubt. For the observation is of the position of the stars, which they call constellations, at the time when the person was born about whom these wretched men are consulted by their still more wretched dupes. Now it may happen that, in the case of twins, one follows the other out of the womb so closely that there is no interval of time between them that can be apprehended and marked in the position of the constellations. Whence it necessarily follows that twins are in many cases born under the same stars, while they do not meet with equal fortune either in what they do or what they suffer, but often meet with fates so different that one of them has a most fortunate life, the other a most unfortunate. As, for example, we are told that Esau and Jacob were born twins, and in such close succession, that Jacob, who was born last, was found to have laid hold with his hand upon the heel of his brother, who preceded him. Now, assuredly, the day and hour of the birth of these two could not be marked in any way that would not give both the same constellation. But what a difference there was between the characters, the actions, the labors, and the fortunes of these two, the Scriptures bear witness, which are now so widely spread as to be in the mouth of all nations.

34. Nor is it to the point to say that the very smallest and briefest moment of time that separates the birth of twins, produces great effects in nature, and in the extremely rapid motion of the heavenly bodies. For, although I may grant that it does produce the greatest effects, yet the astrologer cannot discover this in the constellations, and it is by looking into these that he professes to read the fates. If, then, he does not discover the difference when he examines the constellations, which must, of course, be the same whether he is consulted about Jacob or his brother, what does it profit him that there is a difference in the heavens, which he rashly and carelessly brings into disrepute, when there is no difference in his chart, which he looks into anxiously but in vain? And so these notions also, which have their origin in certain signs of things being arbitrarily fixed upon by the presumption of men, are to be referred to the same class as if they were leagues and covenants with devils.